Today, a body temperature of around 37 ° C is considerednormal. However, normal human body temperature can fluctuate by several degrees. Factors such as age, environment, weight, height, gender and even time of day play a role in the readings of the thermometer. But what body temperature was considered normal in the past? According to a study published in the eLife open access journal, human body temperature is lower today than it was two centuries ago. The authors of the work argue that starting in 1851 - it was then that the first systematic records were collected - the temperature of the human body began to gradually decrease.
What temperature is considered normal?
36.6 ° C gold standard based onthe work of the German physician Karl Reinhold August Wunderlich, who in 1851 collected the first data from 25,000 patients and averaged them. Researchers at Stanford University School of Medicine carefully examined old and new data on human body temperature to find out whether differences can be explained by equipment and methods that have been used in the past.
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During the study, a team of specialists comparedtemperature indicators from a number of sources dating from 1862–2017. In total, the researchers analyzed the performance of more than 677,000 subjects. Based on the evidence, they found that the average temperature in men fell to about 36.3 ° C. The average temperature in women also decreased, although not so significantly, to about 36.6 ° C. Thus, scientists were able to document that from the middle of the 19th century the human body temperature has been steadily decreasing.
Moreover, researchers have confirmed someWunderlich’s early findings, including that the body temperature of young people at rest is higher than that of adults, and the body temperature of women is slightly higher than that of men. Taking into account the method of measuring temperature, as well as all the known data on the instruments used, the researchers came to the conclusion that our bodies are really cooling. But why?
Why is the human body temperature lower today than 160 years ago?
Although the definition of the cause, bywhich we cool beyond the scope of the study, the authors proposed several possible explanations. When Dr. Wunderlich took the measurements, the average life expectancy was only 38 years, and body temperature averaged 36.9 ° C. Moreover, in those years, chronic infections were widespread, from tuberculosis to syphilis. Since average body temperatures tend to decrease with age and increase with infection, it could be that young people suffered from chronic diseases and therefore their bodies were hotter.
Also do not forget about the achievements in medicine- since inflammatory processes often lead to an increase in body temperature, the use of anti-inflammatory drugs, such as aspirin, can also play the role of a gradual “cooling”. In addition, unlike an ordinary citizen of the 19th century, most of us today spend most of our lives in a climate-controlled environment, which can affect the readings of the thermometer.